Field of the Invention
The present invention relates to a rare-earth magnet, a method of manufacturing the rare-earth magnet, and a rotator.
Related Background Art
R—T—B-based rare-earth magnets containing a rare-earth element R, a transition metal element T such as iron (Fe) or cobalt (Co), and boron (B) have excellent magnetic characteristics (see Japanese Patent Application Laid-Open No. 2001-196215, Japanese Patent Application Laid-Open No. 62-192566, Japanese Patent Application Laid-Open No. 2002-25812, and International Publication Pamphlet No. 2006/112403). However, the rare-earth magnets tend to be poor in corrosion resistance, since they are mainly composed of rare-earth elements which are easy to oxidize. Therefore, protective layers made of resins, plating, and the like are often provided on surfaces of magnet matrixes in order to improve the corrosion resistance of the rare-earth magnets.